So what exactly is glaucoma? I asked Dr. Sungjun Hwang, my Eye Care Center ophthalmologist since 1999, to provide a simple description.
“Glaucoma is a disease of the optic nerve,” he explained. “As the optic nerve becomes more damaged, it is less able to transmit the visual information to the brain, resulting in a decline in peripheral vision and may cause you to go blind if untreated.
The optic nerve has the all-important job of transferring visual information from the eye’s retina to the vision centers of the brain. In glaucoma’s late stages, the eye can literally bulge into the site where the optic nerve inserts into the back of the eye ( a phenomenon known as “cupping”).
Your eyes produce aqueous humor, a clear liquid that nourishes them and keeps them inflated. As new aqueous flows in, the same amount should drain out. With open-angle glaucoma, the fluid doesn’t drain properly, builds up and causes an increase in intraocular pressure.
Much less common is angle-closure glaucoma, where the eye’s drainage angle becomes blocked. Pressure can progress slowly or rapidly. When it’s rapid, it’s an acute attack and a medical emergency. Caught in time, it’s treatable by laser treatment or surgery.
Several factors go into a glaucoma diagnosis. A doctor will check intraocular pressures and perform a dilated eye exam to view the optic nerve. A patient takes a visual field test to identify a complete field of vision, a baseline that is repeated at least annually to monitor any vision loss.
Another test checks the drainage angle in the eye. And a newer imaging test, optical coherence tomography (OCT), takes cross-section pictures of your retina to evaluate the optic nerve.
Family history is important and medication history is, too. Some medications affect eye pressures.